In addition to Avataar, Viswanathan leads his eponymous quartet and Sundar's Induswest Project, and performs and records with the world music ensemble Jaffa Road. He has also appeared with many other groups, including the Grammy-nominated Charles Tolliver Big Band, and with leading artists such as Wynton Marsalis, Billy Hart, Jeanne Lee, Joe Lovano, Clark Terry, Al Martino and Kenny Wheeler.

Viswanathan has toured widely in Canada and the US, Europe, South Africa, Japan and Brazil. His performance credits include the Lincoln Center, Count Basie Invitational Jazz Festival and leading jazz clubs the Blue Note and Birdland in New York, and Lula Lounge and Hugh's Room in Toronto.

"...a world of diversity in which tradition and innovation successfully meet... a consistently original and haunting musical voice... Sundar's South Asian musical influences blend seamlessly with the ambitious sonic flows of his fellow jazz musicians to create a different kind of world music." -David Fujino, The Live Music Report